Flame retardant polycarboxy alkyl and aryl phosphonates

ABSTRACT

Flame retardant polycarboxy alkyl and aryl phosphonates having the structural formula: ##STR1## are prepared, wherein R is hydrocarbyl consisting of hydrogen and carbon and substituted hydrocarbyl including C 2  -C 10  alkylene, arylene, C 7  -C 20  alkylene substituted arylene, C 3  -C 20  cycloalkylene, C 4  -C 20  vinylene and derivatives of the foregoing containing non-labile pendant halogens, C 1  -C 6  alkyls, C 1  -C 6  haloalkyls, vinyls, ethers or C 1  -C 6  alkyl alcohol functions. R 1  is hydrocarbyl consisting of hydrogen and carbon and substituted hydrocarbyl including C 1  -C 10  alkyl, aryl, C 7  -C 20  alkyl substituted aryl, C 2  -C 10  alkenyl, phenoxy, C 1  -C 10  alkoxy, aryloxy, or C 3  -C 20  cycloalkyl, and derivatives thereof containing non-labile pendant halogens, C 1  -C 6  alkyls, C 1  -C 6  haloalkyls, vinyls, ethers, or C 1  -C 6  alkyl alcohol functions. R 1  can also be: ##STR2## or OR 4  H wherein R 4  has the same definition as R, and R 4  and R can be the same or different. R 2 , R 3  and R 5  are straight or branched C 1  -C 10  alkylene and can be the same or different. The integer represented by i is from about 2 to about 20 and the integers represented by m and n are different and are 0 to 1. 
     The monomers are prepared by catalyzed transalkylation and the polymers are prepared by polycondensation of the monomers with diols or by polymeric transalkylation.

This is a division, of application Ser. No. 669,004 filed Mar. 22, 1976now U.S. Pat. No. 4,044,074.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates, in general, to a method of preparingpolycarboxy alkyl and aryl phosphonates and polymeric compositionsthereof, and further concerns flame retardant systems incorporating saidphosphorus structures.

2. The Prior Art

Polycarboxy alkylphosphonate monomers are known and are described by A.N. Pudovik et al., Zhurnal Obschei Khimii, Vol. 30, No. 8, pp.2624-2630, August, 1960. Pudovik et al. disclose, among others,compositions having the structural formula: ##STR3## where R' ishydrogen, CH₃, C₂ H₅, or C₃ H₇.

The Pudovik et al. compounds are prepared according to the followinggeneral reaction scheme: ##STR4## where X is I, Br or Cl and R" and R'''are the same or different and have the same definition as R'.

Rates of reaction in the Pudovik et al. method are slow. Moreover,Pudovik et al, employed equimolar quantities of reactants; whichresulted in mixtures of mono- and dicarboxy phosphonates.

SUMMARY OF THE INVENTION

In accordance with the present invention, production yields ofpolycarboxy alkyl and aryl phosphonates can be greatly improved by useof specific catalysts. Also, in accordance with the present invention,polymeric polycarboxy alkyl and aryl phosphonates can be made. Both themonomer and the polymer exhibit excellent flame retardancycharacteristics.

In one aspect of the present invention, there is provided an improvedmethod of preparing polycarboxy alkyl and aryl phosphonates having thestructural formula: ##STR5## wherein R is hydrocarbyl consisting ofhydrogen and carbon and substituted hydrocarbyl including C₂ -C₁₀alkylene, arylene, C₇ -C₂ O alkylene substituted arylene, C₃ -C₂₀cycloalkylene, C₄ -C₂₀ vinylene and derivatives of the foregoingcontaining non-labile pendant halogens, C₁ -C₆ alkyls, C₁ -C₆haloalkyls, vinyls, ethers or C₁ -C₆ alkyl alcohol functions. R¹ ishydrocarbyl consisting of hydrogen and carbon and substitutedhydrocarbyl including C₁ -C₁₀ alkyl, aryl, C₇ -C₂₀ alkyl substitutedaryl, C₂ -C₁₀ alkenyl, phenoxy, C₁ -C₁₀ alkoxy, aryloxy, or C₃ -C₂₀cycloalkyl, and derivatives thereof containing non-labile pendanthalogens, C₁ -C₆ alkyls, C₁ -C₆ haloalkyls, vinyls, ethers, or C₁ -C₆alkyl alcohol functions. R¹ can also be: ##STR6## or OR⁴ H wherein R⁴has the same definition as R, and R⁴ and R can be the same or different.R², R³ and R⁵ are straight or branched C₁ -C₁₀ alkylene and can be thesame or different. The integers represented by m and n are different andare 0 or 1. The integers represented by p and q can be the same ordifferent and are 0 or 1.

Methods of preparing new polymeric compounds also are provided in thepresent invention. These compounds have the structural formula: ##STR7##wherein R, R¹, R² and R³, m and n are as described above and i is aninteger from about 2 to about 20. The compounds can be prepared eitherby polycondensation or polymeric transalkylation.

DETAILED DESCRIPTION OF THE INVENTION

In the polycarboxy alkyl and aryl phosphonates of the present inventionhaving the structural formula: ##STR8## wherein R, R¹, R² and R³, m, n,p and q are as defined above, exemplary R groups include but are notlimited to ethylene. chloroethylene, vinylene, propylene,bromopropylene, propenylene, isopropylene, butylene, butenylene,hydroxybutylene, isobutylene, chlorobutenylyne, pentylene, hexylene,octylene, hydroxyoctylene, decylene, cyclopentylene, cylcohexylene,hydroxycyclopentylene, phenylene, methylphenylene, chlorophenylene, andothers. R groups of low molecular weight, up to about 6 carbon atoms,are preferred as their low volatility allows for easy removal as ROH insubsequent esterification reactions. In the compound of Formula III, Rcan also be hydroxyethylene.

Exemplary R¹ groups include but are not limited to methyl, chloromethyl,hydroxymethyl, ethyl, chloroethyl, hydroxyethyl, vinyl, propyl,bromopropyl, propenyl, isopropyl, butyl, butenyl, hydroxybutyl,isobutyl, chlorobutyl, pentyl, hexyl, octyl, hydroxyoctyl, decyl,cyclopentyl, cyclohexyl, hydroxycyclopentyl, phenyl, methylphenyl,chlorophenyl, carbalkoxymethyl, carbalkoxyethyl, and others.

Pendant halogens on the R and R' groups include halogens having amolecular weight between 35 and 80, such as chlorine and bromine.

Exemplary R², R³ and R⁵ groups include but are not limited to methylene,ethylene, propylene, isopropylene, butylene, isobutylene, tert-butylene,pentylene, hexylene, heptylene, octylene, nonylene and decylene.

The method comprises contacting a reactant having the structuralformula: ##STR9## where R¹, m and n are as defined above and R⁶ ishydrocarbyl consisting of hydrogen and carbon and substitutedhydrocarbyl including C₁ -C₆ alkyl, allyl, dihaloalkyl, benzyl andderivatives thereof containing non-labile pendant halogens; with otherreactants having the structural formulas:

    X--R.sup.2 --CO.sub.2 (R)--.sub.p H                        (V)

and

    X--R.sup.3 --CO.sub.2 (R)--.sub.q H                        (VI)

wherein R, R² and R³ and p and q are as defined above and X is halogenhaving a molecular weight between about 35 and 80, in the presence of anucleophilic catalyst selected from the group consisting of tetraethylammonium chloride, sodium carbonate, sodium bicarbonate, lithiumchloride, and other nucleophilic salts.

The following equation (2) is representative of the reaction: ##STR10##wherein R, R¹, R⁶ X, n and m are as defined above.

Reactants utilized in the method described above are generally employedin stoichiometric amounts, although an excess of either reactant can beused if desired. The quantity of undesired side products however, isminimized by the use of approximately stoichiometric amounts ofreactants.

The method is carried out at elevated temperatures from about 120° and250° C. and generally between about 160° and 200° C.

Reaction times can vary over relatively wide ranges and can easily bedetermined by one skilled in the art. Factors affecting reaction timeinclude reactant and catalyst concentrations and temperature. Increasesin temperature and catalyst concentration result in decreased reactiontimes. Dilute reactants require longer reaction times than concentratedreactants. Typical reaction times are from about 1 to about 12 hours.

The method described above can conveniently be effected by introducingthe individual reactants and catalyst into any reaction zone that can beheated to the reaction temperature. The zone is generally provided witha condenser for removal of volatile components. A thermometer,thermocouple or other conventional means can be used to monitortemperature. The reaction can be carried out in a continuous orbatch-type system as desired.

The products of the reaction are generally purified by vacuumdistillation but other conventional methods such as extraction orsublimation can be used.

The identification of products can be achieved by infrared spectra, ¹ Hnuclear magnetic resonance spectra and ³¹ P nuclear magnetic resonancespectra, boiling point analysis and elemental analysis.

Typical yields of the above-described method of the present inventionare from about 75% to about 90%, as compared to the prior art whereinthe catalyst is not employed. The prior art yield is generally about20%.

Illustrative of the compounds corresponding to structural formula (III)which can be prepared by the method of the present invention are:##STR11##

The products of the present invention are useful as flame retardants forpolyurethane foams, unsaturated polyesters, acrylates, textiles,cellulosics, epoxy resins, aminoplasts and phenolics. In the manufactureof plastics, the products can be directly used as flame retardantcomponents. For example, said products can transesterify into anunsaturated polyester alkyd composition, thereby becoming an integralpart of the plastic.

The products also can be used as intermediates to make phosphorusoligomers. These oligomers, in turn, can be used as flame retardants,and because of their higher molecular weight will exhibit gooddurability.

The methods of preparing new polymeric compounds having the structuralformula: ##STR12## wherein R, R¹, R² and R³, and m and n are asdescribed above and i is an integer from about 2 to about 20, arepolycondensation or polymeric transalkylation.

Polycondensation comprises contacting a reactant having the structuralformula (III) with a reactant selected from the group consisting ofpolyols having the structural formula:

    R.sup.7 (OR.sup.8)g                                        (VIII)

wherein R⁷ is hydrocarbyl consisting of hydrogen and carbon andsubstituted hydrocarbyl, and polyester; including C₁ -C₂₀ alkylene andC₇ -C₂₀ alkenylene, substituted arylene and derivatives of the foregoingcontaining non-labile pendant halogens, C₁ -C₆ alkyls, C₁ -C₆haloalkyls, C₂ -C₆ alkenyls and C₂ -C₆ haloalkenyls. R⁸ is selected fromhydrogen and ##STR13## where R² and X are as defined above. The integerrepresented by g is from about 1 to about 10.

Exemplary polyols of the formula (VIII) include but are not limited tothe following: ##STR14## wherein a and b are the same or different andare integers from about 2 to about 4.

Other exemplary polyols of the formula (VIII) include sucrose polyetherpolyols and polyols of maleic acid, phthalic acid and ethylene glycol.

The reactants having the structural formalae (III) and (VIII) arecontacted in the presence of a conventional transesterification catalystsuch as stannous octoate, toluene sulfonic acid, manganese acetate,tetraalkyl titanoate, antimony oxide, tetraalkyl zirconate, tributoxyantimony, sulfuric acid, acidic clays, acidic sulfonic acid and ionexchange resins.

The equation representative of the polycondensation reaction is asfollows: ##STR15## wherein R, R¹, R², R³ and R⁷ and m, n, g and i are asdefined above.

While the molar ratio of phosphonate monomer to polyol will generallyvary from about 0.5 to about 2.0, the preferred range for minimalbyproduct formation is from about 0.8 to about 1.2.

A catalyst concentration ranging from about 0.001 to about 10% can beused. Generally, however, a range from about 0.05 to about 4.0% isemployed for efficiency of catalyst function.

The polycondensation process of the present invention is generallycarried out at a temperature of from about 100° C. to about 220° C.Temperatures of from about 150° C. to about 200° C. are preferred for arapid transesterification rate consonant with keeping below thedecomposition temperature of the reactants.

Reaction times can vary over relatively wide ranges and can easily bedetermined by one skilled in the art. Factors affecting reaction timeinclude reactant and catalyst concentrations and temperature. Increasesin temperature and catalyst concentration result in decreased reactiontimes. Dilute reactants require longer reaction times than concentratedreactants. Typical reaction times are from about 1 to about 12 hours.

The polycondensation method of the present invention can conveniently beeffected by introducing the individual reactants and catalyst into anyreaction zone that can be heated to the reaction temperature. The zoneis generally provided with a condenser for removal of volatilecomponents. A thermometer, thermocouple or other conventional means canbe used to monitor temperature. The reaction can be carried out in acontinuous or batch-type system as desired.

The products of the reaction are neutralized by treatment with analkylene oxide such as ethylene oxide, epichlorohydrin, propylene oxideor a higher molecular weight diepoxide at about 50°-120° C. over aperiod of several hours. Catalysts such as stannous octoate andtributoxy antimony can accelerate this neutralization.

Devolatilization can be completed by application of a vacuum followed bypassage of the products through a wiped-film evaporator or other similartypes of equipment as are well-known in the art.

The identification of the products is generally achieved by elementaland infrared analysis or other suitable methods as are well known in theart.

The yield of the reaction is generally between about 85 and 95% oftheoretical yield.

Another method, polymeric transalkylation, comprises contacting aphosphonate having the structural formula: ##STR16## as defined above,with a dihalo bis(ester) reactant having the structural formula:##STR17## wherein R, R², R³ and X are as defined above, in the presenceof a catalyst.

Exemplary phosphonates having the structural formula IV include but arenot limited to the following: ##STR18##

Exemplary dihalo bis(acetate) reactants having the structural formula IXinclude but are not limited to the following: ##STR19## where a+b=4 anda≧2.

The catalyst is generally a nucleophilic salt such as tetraethylammonium chloride, sodium carbonate, sodium bicarbonate, lithiumchloride and others.

The equation (4) representative of the polymeric transalkylationreaction is as follows: ##STR20##

Molar reactant ratios of phosphonate to dihalo bis(esters) can vary fromabout 0.5 to about 2.0 although greater or lesser amounts can be used.Generally, reactant ratios ranging from about 0.8 to about 1.2 are used.

In equation (4), when R¹ is a pendant carboxylic acid function thepolymer can be trifunctional.

The polymeric transalkylation process of the present invention iscarried out at a temperature of from about 120° C. to about 230° C., andpreferably from about 150° C. to about 190° C. for optimum reaction timeand avoidance of product decomposition.

Reaction times can vary over relatively wide ranges and can easily bedetermined by one skilled in the art. Factors affecting reaction timeinclude reactant and catalyst concentrations and temperature. Increasesin temperature and catalyst concentration result in decreased reactiontime. Dilute reactants require longer reaction times than concentratedreactants. Typical reaction times are from about 1 to about 10 hours.

The polymeric transalkylation method of the present invention canconveniently be effected by introducing the individual reactants andcatalyst into a reaction zone that can be heated to the reactiontemperature. The zone is generally provided with a condenser for removalof volatile components. A thermometer, thermocouple or otherconventional means can be used to monitor temperature. The reaction canbe carried out in a continuous or batch-type system as desired.

The products of the reaction are neutralized by treatment with analkylene oxide such as ethylene oxide, epichlorohydrin, propylene oxide,or a higher molecular weight diepoxide over several hours at about50°-120° C. Devolatilization is performed under reduced pressurefollowed by passage through a wiped-film evaporator or other similartypes of equipment as are well known in the art.

The identification of the products is achieved by elemental and infraredanalysis or other suitable methods as are well known in the art.

The yield of the reaction is generally between about 75 and 95% oftheoretical yield.

Illustrative of the polymers which can be prepared by the methods of thepresent invention are: ##STR21##

Unsaturated polyesters can be flame retarded by incorporation onto thebackbone of the polyester alkyd of phosphonates having the structuralformula: ##STR22## wherein R, R¹, R², R³, m, n and i are as definedabove. Such backbone incorporation gives permanency of the phosphorousflame retardant substituent.

There are several procedures for accomplishing such incorporation andtwo are described herein.

In one method, the previously described phosphorus intermediate havingstructure: ##STR23## is condensed together with the general constituentsof a polyester resin. Said resins generally comprise a mixture ofglycols, e.g. propylene or diethylene glycol, unsaturated dibasic acidsor anhydrides, e.g. fumaric acid or maleic anhydride, and, optionally, asaturated dibasic acid or anhydride, e.g. isophthalic, phthalic,chlorendic, bromated tetrahydrophthalic, tetrabromophthalic andtetrachlorophthalic acids and their respective anhydrides, which servesto control the reaction and modify the properties of the resultingproduct. These constituents are heated together in a combination havingequivalent molar concentrations of alcohol and carboxy functionality. Tothe thus prepared fluid polyester, a reactive monomer, e.g. styrene,diallyl phthalate, diallyl isophthalate, methylmethacrylate or triallylcyanurate, is then usually added and a peroxide catalyst, e.g. benzoylperoxide, is introduced in order to catalyze the final copolymerizationreaction. These polyesters, or unsaturated polyesters as they are oftenreferred to, are thermosetting and are widely used in reinforcedplastics and in the potting of electrical components.

In another procedure, chloroacetic acid is employed as one of thepolyester components. Subsequent to polyesterification, a dialkyl,alkylphosphonate or a dialkyl arylphosphonate (e.g. dimethylmethylphosphate) is made to transalkylate in situ with the chloroacetateend groups. This results in the formation of long chain or highermolecular weight crosslinked polyesters from smaller chain polyesters. Ageneral equation for this would be: ##STR24## wherein R, R¹, R², R³, X,i and g are as defined above, and the polyester is the residue derivedfrom polyfunctional unsaturated or saturated acids (with or withouthalogen) and polyols.

The products of the present invention have numerous uses as illustratedin the following general outline:

1. lubricant additives

a. anti-wear

b. extreme pressure imparting

c. antioxidant

d. viscosity controlling

2. metal stabilizers

3. emulsifiers

4. surfactants

5. antistatic agents for textiles

6. flame retardants

a. textiles

b. plastics

c. lubricants

7. plasticizers

8. antioxidants for plastics

among others. Methods of using the products of the present invention forthe foregoing utilities will be apparent to those skilled in the art onthe basis of the present disclosure.

With respect to utilizing the products of the present invention to flameretard plastics, the following plastics are typical of those that can beused: unsaturated polyesters, cross-linked polyesters, polyacrylates,polymethacrylates, polyvinyl acetates, polyvinyl alcohols,polyvinylacetals, polyurethanes, polyisocyarates, polyureas, phenolicresins, cellulose acetates, cellulose butyrates, cellulose nitrate,epoxy resins, aminoplasts, (including aminoplasts such as urea--CH₂ O,melamine--CH₂ O, alkylated melamines and others) nylon, polyethyleneterephthalate, polycarbonates, polyphenylene ethers, acrylonitrilebutadiene styrene terpolymer, polystyrene, silicones, polyacrylonitrile,polyethylene, polypropylene, polyvinylchloride and others. Flameretardant amounts of the products of the present invention in plasticsare generally in the range from about 0.2 percent to about 8 percentphosphorus by weight. The flame retardant plastics of the presentinvention can be produced by combining the products of the presentinvention with plastics by admixture or incorporation in the polymerbackbone.

The present invention will be more fully illustrated in the Exampleswhich follow:

EXAMPLE 1 ##STR25##

The monomer, bis(ethylacetoxy) methylphosphonate, was prepared bytransalkylation. A reactor was charged with 620 g. (5.0 mole) ofdimethyl methylphosphonate and 10 g. of tetraethylammonium chloride. Themixture was heated under nitrogen to 175° C. To this was added 1,372 g.(11.2 mole) ethyl chloroacetate over a 6 hour period while maintaining apot temperature of 175° C. A further two hours at this temperature wasrequired for reaction completion as noted by the collection of 490 g.(9.7 mole) of methyl chloride in a cold trap. The product was removed bydistillation. A colorless liquid (1119 g., 4.15 mole, 83% yield) wasrecovered having a boiling point of 148° C./0.3 mm. The H-nmr spectrumconsisted of signals at τ 8.72 (6H, triplet, J=7 Hz, OCH₂ CH₃), τ 8.39(3H, doublet, J=19 Hz, CH₃ P), τ 5.78 (4H, quartet, J= 7Hz, OCH₂ CH₃)and τ 5.42 (4H, doublet, J=12 Hz, CH₂ OP). In the ³¹ P-nmr spectrum asignal was observed at -35 ppm relative to ortho phosphoric acid. Theobserved phosphorus analysis was 11.7% which corresponds to thetheoretical value of 11.5%.

EXAMPLE 2 ##STR26##

Bis(methylacetoxy) methylphosphonate was prepared as in the previousexample. The reaction was charged with 248 g. (2.0 mole) of dimethylmethylphosphonate and 2 g. of tetraethylammonium chloride. Nitrogen wasused to purge the system after which the contents were heated untilreflux (177° C.). Methyl chloroacetate (504 g., 4.6 mole) was then addeddropwise over a period of 3 hours at such a rate as to maintain the pottemperature between 165°-180° C. A -78° C. cold trap leading from thereaction was found to contain 180 g. (3.55 mole) of methyl chlorideby-product. Vacuum distillation of the pot mixture (bp 136°-140° C./0.6mm) gave 312 g. (1.3 mole) of bis(methylacetoxy) methylphosphonaterepresenting a 67% yield.

The 'H-nmr of this compound exhibited signals at τ 8.38 (3H, doublet,J=18 Hz, CH₃ P), τ 6.26 (6H, singlet, OCH₃) and τ 5.38 (4H, doublet,J=12 Hz, POCH₂).

EXAMPLE 3A ##STR27##

Polycondensation of bis(methylacetoxy) methylphosphonate (96 g., 0.40mole) with ethylene glycol (24.8 g., 0.40 mole) was accomplished byheating these reagents at 180° C. for 3 hours in the presence of 0.3 g.stannous octoate. Methanol (16 g.) was continuously removed as itevolved from the reaction. A clear viscous liquid of acid number 12.3mg. KOH/g. remained in the pot. Addition of ethylene oxide at 75° C.over several hours reduced the acid number to 0.56. Residual volatileswere removed by passing the product through a wiped-film evaporator(100° C./0.3 mm). Obtained were 88.7 g. of a clear white liquid having aphosphorus content of 11.8% and hydroxyl number of 159.

EXAMPLE 3B

As regards the previous example, other reactant concentration ratiopolymers can be prepared in which final phosphorus content and hydroxylfunctionality can be varied to suit the end application. For example, 96g. (0.40 mole) of bis(methylacetoxy) methylphosphonate wastransesterified with 18.6 g. (0.30 mole) of ethylene glycol using 0.3 g.stannous octoate as catalyst. After heating for 4 hours at 163°-198° C.under nitrogen, a total of 12.9 g. methanol had evolved and been removedby distillation. Subsequently, ethylene oxide was bubbled slowly intothe product at 75° C. over 5 hours to insure neutralization. Residualvolatiles were removed by a 20 minute vacuum strip at 80°/18 mm, whichwas followed by passage of product through a wiped-film evaporator (100°C./0.3 mm). A clear, pale yellow, viscous liquid was thus obtained (84g.). Analysis of this liquid indicated an acid number of 0.56, anhydroxyl number of 96 and a phosphorus content of 8.87%.

EXAMPLE 4 ##STR28##

Polycondensation of bis(ethylacetoxy) methylphosphonate (134 g., 0.5mole) with ethylene glycol (27.9 g., 0.45 mole) was accomplished byheating these reagents at 165°-180° C. for 4 hours in the presence of0.3 g. stannous octoate under nitrogen. Ethanol (29.5 g.) wascontinuously removed as it evolved from the reaction. The produ ctexhibited an acid number of 19 mg KOH/g at this junction. Neutralizationwas accomplished by treating the pot residue with ethylene oxide forseveral hours at 100° C. Residual volatiles were removed by firstapplying an aspirator vacuum for 30 minutes at 80° C. and then passingthe product through a wiped-film evaporator (100° C./0.1 mm.). A yellowsemi-viscous liquid was obtained (100 g). Analysis revealed an acidnumber of 0.28, an hydroxyl number of 104 and a phosphorus content of12.2%.

EXAMPLE 5 ##STR29##

A typical esterification reactor apparatus, fitted with a Dean-Starktrap, was employed to condense 754 g (8.0 mole) of chloroacetic acidwith 272 g (4.0 mole) of ethylene glycol. Stannous octoate (3.0 g) wasused as catalyst while 35 ml of V, M and P naphtha was used as a waterazeotrope solvent. The reactants were heated between 132°-165° C. undernitrogen. Condensation appeared complete after 7 hours as evidenced bythe collection of 141.4 g. water relative to a theoretical value of 144g. The product was diluted in 1500 ml methylene chloride and washedsuccessively with water, aqueous sodium carbonate solution and wateronce again. The organic layer was separated, dried over MgSO₄ andsolvent stripped on a rotary evaporator in vacuo. A clear, colorlessliquid (710 g.) was obtained representing an 83% yield of the ethyleneglycol bis-ester of chloroacetic acid.

Ethylene glycol bis-ester of chloroacetic acid (129 g., 0.60 mole) wasreacted with 124 g. (1.0 mole) of dimethyl methylphosphonate using 0.5g. of tetraethylammonium chloride as a catalyst. Transalkylation wasperformed at 164°-185° C. over a 4 hour period. A total of 56.2 g. (1.1mole) of methyl chloride was recovered as by-product from an attached-78° C. cold trap. Neutralization of the product (acid number = 7.3 mgKOH/g) was accomplished by the addition of ethylene oxide over a twohour period at 100° C. Volatiles were stripped away under aspiratorvacuum at 100° C. over a 30 minute interval. Next, the product was fedthrough a wiped-film evaporator (100° C./0.1 mm). Obtained were 142.5 gof a viscous orange fluid. The material had an acid number of 0.07,hydroxyl number of 36.9%.

EXAMPLE 6 ##STR30##

An esterification reactor fitted with a Dean-Stark trap was charged with104 g. (1.1 mole) of chloroacetic acid, 123 g. (0.5 mole) of1,4-dibromo-2-butenediol, 1 g. stannous octoate and 80 ml V, M and Pnaphtha. The reactants were heated under nitrogen at 145°-153° C. After14 hours, 17.0 g. of hot water condensate had collected in the trap(theory=18 g.). The product was diluted in 300 ml methylene chloride andwashed successively with water, aqueous sodium carbonate and then water.The organic layer was separated, dried over MgSO₄ and solvent strippedin a rotatory evaporator in vacuo. A white solid weighing 172.6 g. (0.87mole) was obtained representing an 87% yield. The crystals melted at73°-74° C. An infrared spectrum indicated absence of OH but presence ofbands at 3030, 3010 cm⁻¹ (C═C) and 1765 cm⁻¹ (C═O).

The dibromobutene diol bis-ester of chloroacetic acid (60 g., 0.14 mole)was reacted with 49.6 g. (0.40 mole) of dimethyl methylphosphonate inthe presence of 0.5 g. tetraethylammonium chloride as catalyst.Transalkylation was accomplished at 180°-205° C. over a 3 hour period.During the reaction 17.2 g. (0.3 mole) of methyl chloride evolved andwere collected in a -78° C. cold trap. The brown pot residue wasdissolved in 150 ml methylene chloride and washed with two portions 200ml water. After separating the organic layer, it was dried with MgSO₄.Solids were then filtered and solvent removed. A viscous liquid weighing50.3 g. was recovered.

EXAMPLE 7

A reactor was charged with 40.9 g. (0.10 mole) of the dibromobutenediolbis-ester of chloroacetic acid, 14.9 g. (0.12 mole) of dimethylmethylphosphonate and 0.2 g. tetraethylammonium chloride. Thesereactants were heated at 205° C. over a 2 hour period. Methyl chlorideby-product weighing 43.0 g. was recovered from an attached cold trap.The product was taken up in methylene chloride and washed with water.After the usual work-up procedure, 43.0 g. of a semi-solid remained.

    __________________________________________________________________________    Examples 8 - 12                                                               End group variations of the polymer described in Example 5 can be made by     changing                                                                      reactant ratios. These examples are outlined in the following table:          Examples            8     9      10    11    12                               __________________________________________________________________________    Reagents:                                                                     Bis-ester (g., mole)                                                                              215, 1.0                                                                            162, 0.75                                                                            108, 0.5                                                                            129, 0.6                                                                            129, 0.6                         Dimethyl methylphosphonate (g., mole)                                                             124, 1.0                                                                            124, 1.0                                                                             113, 0.9                                                                            149, 1.2                                                                            174, 1.4                         Tetraethylammonium chloride (g.)                                                                  1.0   0.5    0.5   0.5   0.5                              Conditions:                                                                   Reaction Time (hours)                                                                             2     3      3     4     3.3                              Reaction Temperature (° C.)                                                                161-175                                                                             162-175                                                                              152-181                                                                             178-190                                                                             150-166                          Acid Number:                                                                  Before ethylene oxide treatment                                               (mg KOH/g)          8.4   5.6    5.6   7.8   5.6                              After ethylene oxide treatment                                                                    0.56  0.1    0.12  0.10  0.56                             (mg KOH/g)          0.56  0.1    0.12  0.10  0.56                             Products:                                                                     Methylchloride (g., mole)                                                                         89, 1.1                                                                             65, 1.3                                                                              47, 0.93                                                                            57, 1.1                                                                             57, 1.1                          Residual polymer (g)                                                                              238   175    117   177   163                              Analysis:                                                                     Hydroxyl Number (mg KOH/g)                                                                         --    --    36.8  53.2  80.1                             Phosphorus (%)       --   12.9   14.0  14.3  14.5                             Chlorine (%)         --   1.9    0.48  0.48  0.53                             __________________________________________________________________________

EXAMPLE 13 Preparation of Control Resin

A one-liter reactor kettle equipped with thermometer, stirrer, inert gassparge tube, steam heated reflux column and total condenser was chargedwith 285.8 g. (1.0 mol) of tetrachlorophthalic anhydride, 89 g. (0.9mol) of maleic anhydride, 124 g. (2.0 mol) of ethylene glycol and 0.1 g.of hydroquinone inhibitor. The reactants are heated slowly to 168° C.over a 7 hour period and then maintained at 195° C. for 11 hours.Throughout the reaction period, a slow stream of nitrogen is used topurge volatiles. Water of condensation (23.7 g.) was continuouslyremoved through the heated reflux column and total condenser in a mannerso that all the refluxing glycol was returned to the reactor. A paleyellow alkyd resin remained behind having an acid number of 21 mg.KOH/g. Upon cooling the alkyd resin down to 120° C., 216 g. of styrenecontaining 0.4 g., hydroquinone was added with efficient mixing toinsure a homogeneous solution. Heat was then removed and the polyesterallowed to cool; within 30 minutes the temperature had subsided to 80°C. The resultant resin contained by analysis 20.2% chlorine.

EXAMPLE 14 Preparation of Phosphorus Containing Polyester by the In SituTransalkylation of Chloroacetic Acid-Dimethyl Methylphosphonate

The aforedescribed reactor was charged with 89 g. (0.9 mol) of maleicanhydride, 285.8 g. (1.0 mol) of tetrachlorophthalic anhydride, 94.5 g.(1.0 mol) of chloroacetic acid, 162 g. (2.6 mol) of ethylene glycol and0.1 g. of hydroquinone inhibitor. Heat was gradually applied to thereactants while a slow nitrogen stream assisted in the removal of water.Temperatures of 150° C., 170° C. and 190° C. were attained after 1.5, 5and 7 hours, respectively. At the end of 13 hours a total of 52.8 g.volatiles had been collected. One gram of tetraethylammonium chloridewas now added, followed by 62 g (0.5 mol) of dimethyl methylphosphonateover a 15 minute period. A temperature of 190° C. was maintained over a4.5 hour period for this transalkylation step. By-product methylchloride (46.1 g.) was continuously collected in a cold trap at -78° C.Subsequently, the reaction mixture was cooled to 110° C. The acid numberwas 2.2 mg. KOH/g. Styrene (216 g.) containing 0.4 g., hydroquinone wascombined with the alkyd resin using vigorous stirring. A mixture wasallowed to cool rapidly. A tan resin resulted having a phosphoruscontent of 2.2%.

EXAMPLE 15 Preparation of Phosphorus Containing Polyester UsingBis(ethylacetoxy) Methylphosphonate as Reactive Monomer

Into a one-liter condensation-reaction equipped reactor were placed285.8 g (1.0 mol) of tetrachlorophthalic anhydride, 49 g. (0.5 mol) ofmaleic anhydride, 136.4 g. (2.2 mol) of ethylene glycol, 134 g. (0.5mol) of bis(ethylacetoxy) methylphosphonate and 0.1 g. of hydroquinone.These reagents were heated together at 165°-180° C., for 7 hours.Volatiles weighing 45.1 g. were removed from the condensate.Subsequently, the alkyd resin, having an acid number of 76 mg KOH/g. wascooled to 80° C. Styrene (220 g.) containing 0.6 g. hydroquinone wasblended into the alkyd resin. The product was a light yellow resincontaining 2.2% phosphorus and 17.4% chlorine.

Example 16

The synthesis of this polyester resin sample was similar to thatdescribed in Example 14. Reagent quantities and product analysis isdetailed in Table I.

Example 17

This chlorendic acid based control resin was prepared in a mannersimilar to that described in Example 13. Reagent quantities and productanalysis is detailed in Table I.

Example 18

A chlorendic acid type resin was prepared incorporating phosphorus usingbis (ethylacetoxy) methylphosphonate as a reactive monomer. Theexperimental details are similar to those of Example 15. See Table I forreagent quantities and product analysis.

Example 19

The synthesis of this polyester resin sample was similar to thatdescribed in Example 14. Table I details reagent quantities and productanalysis.

                                      Table I                                     __________________________________________________________________________    Example No.      13   14   15   16   17   18   19                             __________________________________________________________________________                     Control             Control                                  % Cl             20.2 18.0 17.4                                                                              11.7  22.5 19.2 22.6                           % P                   2.2  2.2 5.0        2.3  2.2                            Maleic Anhydride (mole)                                                                        0.9  0.9  0.5 0.5   1.3  0.8  0.9                            Chlorendic Anhydrice (mole)          0.7  0.7  0.7                            Tetrachlorophthalic Anhydride                                                 (mole)           1.0  1.0  1.0 0.5                                            Chloroacetic Acid (mole)                                                                            1.0      2.0             1.0                            Ethylene Glycol (mole)                                                                         2.0  2.6  2.2 2.2   2.2  2.2  2.2                            Bis(ethylacetoxymethyl-                                                       phosphonate) (mole)        0.5            0.5                                 Dimethyl methylphosphonate                                                    (mole)                0.5      0.5             0.5                            Oxygen Index (%) 26.1 29.8 28.1                                                                              29.1  25.5 30.3 29.1                           HLT-15           6c/       100/                                                                              100/  24/  100/ 100/                           (Rating/Flame Time                                                                             --        193 25    --   117  45                             in seconds)                                                                   __________________________________________________________________________

Example 20 Polyester Evaluation

To evaluate the fire retardant properties of these polyester resins,1/8" thick glass reinforced laminated panels were prepared from threelayers of 11/2 oz. per square foot fiberglass mat. Resin cure wascatalysed with either a 1% methyl ethyl ketone peroxide - 0.1% dimethylaniline promotor system or a 1% benzoyl peroxide - 0.1% dimethyl anilinepromotor system. All samples were post-cured for one hour at 100° C.

Flammability of the polyester compositions was measured by the OxygenIndex Test and/or the HLT-15 test.

The Limiting Oxygen Index Test -

This procedure, also known as the LOI method, is described by Fenimoreand Martin in Modern Plastics, November, 1966. The LOI method directlyrelates flame retardancy to a measurement of the minimum percentageconcentration of oxygen in an oxygen-nitrogen mixture which permits thesample to burn; the LOI being calculated as follows: ##EQU1## Thus, ahigher LOI is indicative of a higher degree of flame retardancy.

The HLT-15 Flame Test -

This test is conducted in a draft-free cabinet on 8" × 1/2" × 1/8"samples suspended vertically from the top. A bunsen burner flame 5" longwith a 11/2" long inner blue cone is inclined at an angle of 20° fromthe vertical so that the blue cone just touches the bottom tip of thesample. Five specimens of each sample are tested to the followingschedule:

    ______________________________________                                        Application On Time (seconds)                                                                            Off Time                                           ______________________________________                                        1            5             10                                                 2            7             14                                                 3           10             20                                                 4           15             30                                                 5           25             50                                                 ______________________________________                                    

A rating of 4 is assigned each time a sample extinguishes during the offtime. A rating of O is assigned and testing ended on a specimen if itcontinues to burn beyond the alloted time. Should all five samples passthe 5 applications, a rating of 100 is attained. The elapsed burningtimes are then summed in order to establish an additional rating of thesample.

As seen from Table 1, polyesters containing the acetoxymethylphosphonate linkages have Oxygen Index values 2-3% and 4-5% abovethose of the control tetrachlorophthalic anhydride and chlorendicanhydride based resins, respectively. Results of HLT-15 test alsoindicate significantly improved performance of acetoxy methylphosphonatecontaining polyester over control resins.

Example 21 ##STR31##

A reactor was charged with 140 g (1.0 mol) of trimethyl phosphate and 2g. of tetraethylammonium chloride. The mixture was heated until reflux.Ethyl chloroacetate (368 g., 3.0 mol) was added dropwise over a 5.5 hourperiod maintaining a temperature of 160°-180° C. throughout. After 15hours, methyl chloride by-product evolution had ceased and the reactionwas thus terminated.

A total of 135 g. (2.7 mol) of methyl chloride had collected in anattached cold trap. The product was subsequently distilled under vacuum(bp 195° C./0.20 mm) to give 190 g. (0.52 mol) representing a 52% yieldof tris(ethylacetoxy) phosphonate. The proton nmr of this substanceexhibited signals at τ8.75 (9H, triplet J=7Hz, CH₃ CH₂ O) τ5.79 (6H,quartet J=7 Hz, CH₃ CH₂ O) and τ5.32 (6H, doublet J=11.5 Hz, COCH₂ OP).Infrared bands at 1750 (c═O), 1290 and 1215 cm⁻¹ (P═O) were noted.

EXAMPLE 22

The use of the products described in Examples 3A and 3B as flameretardants for polyurethane foams is illustrated.

The foams were prepared by thoroughly mixing sequentially the materials,with the exception of TDI, as listed in Table III below. Toluenediisocyanate (TDI) was introduced last and the formulation mixedvigorously 5-10 seconds followed by a rapid pour into an 8" squarecardboard box.

The degree of flame retardancy of the resulting foams was evaluated bythe Motor Vehicle Safety Standard 302 Flammability Test (MVSS 302).

In this test, a specimen of foam 4" × 1/2" thick by 14" long is heldhorizontally between two U-shaped brackets which allow free access ofair above and below. The specimen is ignited by a bunsen burner and theburning rate in inches/minute is measured. A burn rate below 4"/min. isusually required.

General Motors has an additional interpretation of MVSS 302:

    ______________________________________                                        Does not ignite       DNI                                                     SE before first mark (before                                                  11/2 " total)         SE                                                      SE in less than 31/2" from starting point                                                           SE/NBR                                                  SE after 31/2" from starting point                                                                  SE, & burn rate                                         Burns full length     burn rate                                               ______________________________________                                    

Results of these evaluations are presented in Table III.

                  TABLE III                                                       ______________________________________                                                             Foam                                                     Foam Components (in grams)                                                                      Control  No. 1    No. 2                                     ______________________________________                                        Polyol CP3000 (a 3000                                                                           100      100      100                                       molecular weight triol                                                        from Dow Chemical Company)                                                    Flame retardant from                                                                            --        10      --                                        Example 3A                                                                    Flame retardant from                                                                            --       --       10                                        Example 3B                                                                    Water             4.5      4.5      4.5                                       Silicone (Union Carbide                                                                         1.0      1.0      1.0                                       L-548)                                                                        Amine (A 2:1 blend of                                                                           0.3      0.3      0.3                                       N-ethylmorpholine                                                             and Union Carbide                                                             A-1 catalyst)                                                                 Tin (a 50% stannous octoate                                                                     0.4      0.4      0.4                                       Solution from American Can                                                    Company/called T-10)                                                          Methylene chloride                                                                              3.0      3.0      3.0                                       (blowing agent)                                                               TDI (an 80/20 mixture of 2,4-                                                                    60       60       60                                       and 2,6-toluene diisocyanate)                                                 MVSS 302 Text                                                                             Burns (4.5"/min.)                                                                            SE/NBR   SE                                        ______________________________________                                    

Not only were the materials from Example 3A and 3B good flame retardantsas seen above but the resultant foams possessed excellent physicalproperties. Moreover, the tendency to cause scorch exhibited by manyflame retardants was virtually eliminated with these materials.

Having set forth the general nature and some examples of the presentinvention, the scope is now particularly set forth in the appendedclaims.

What is claimed is:
 1. A flame retardant plastic composition comprisinga plastic in combination with a compound having the formula: ##STR32##wherein R is selected from group consisting of C₂ -C₁₀ alkylene,arylene, C₇ -C₂₀ alkyl substituted arylene, C₃ -C₂₀ cycloalkylene, C₄-C₂₀ vinylene and derivatives of the foregoing containing non-labilependant halogens, C₂ -C₆ alkyl groups, C₁ -C₆ haloalkyl groups, vinylgroups, ether groups and C₁ -C₆ alkyl alcohol groups; R¹ is selectedfrom the group consisting of C₁ -C₁₀ alkyl, aryl, C₇ -C₂₀ alkylsubstituted aryl, C₂ -C₁₀ alkenyl, C₁ -C₁₀ alkoxy, aryloxy, and C₃ -C₂₀cycloalkyl, and derivatives thereof containing non-labile pendanthalogens, C₁ -C₆ alkyl groups, C₁ -C₆ haloalkyl groups, vinyl groups,ether groups, and C₁ -C₆ alkyl alcohol groups, and ##STR33## and OR⁴ Hwherein R⁴ has the same definitions as R, and R⁴ and R can be the sameor different; R², R³ and R⁵ are straight or branched C₁ -C₁₀ alkyleneand can be the same or different; i is an integer from about 2 to about20; the integers represented by m and n are different and are 0 or
 1. 2.The plastic composition of claim 1 wherein total phosphorus content isfrom about 0.2 percent to about 8 percent by weight.
 3. The plasticcomposition of claim 1 wherein said combination is characterized byadmixture of said compound with said plastic.
 4. The plastic compositionof claim 1 wherein the plastic is a polyester and said composition ischaracterized by incorporation of said compound in the polymer backbone.5. The plastic composition of claim 1 wherein said plastic is selectedfrom the group consisting of unsaturated polyesters, cross-linkedpolyesters, polyacrylates, polymethacrylates, polyvinylacetates,polyvinyl alcohols, polyvinylacetals, polyurethanes, polyisocyanates,polyureas, phenolic resins, cellulose acetates, cellulose butyrates,cellulose nitrate, epoxy resins, aminoplasts, nylon, polyethyleneterephthalate, polycarbonates, polyphenylene ethers, acrylonitrilebutadiene styrene terpolymers, polystyrene, silicones,polyacrylonitrile, polyethylene, polypropylene and polyvinylchloride.